JP2008155069A - Method for manufacturing earth and sand alternative material using organic sludge as main raw material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an earth and sand alternative material using organic sludge as a main raw material which has a strength as an earth and sand alternative material, comparable with a natural material, satisfies a profitable manufacturing cost, and prevents the elution of hazardous substances such as heavy metals. <P>SOLUTION: In the method for manufacturing an earth and sand alternative material, at lease one adjuvant among sandy molten slag, concrete debris, glass, recycled material of crushed earthenware, silty coal ash, and gypsum is mixed with the organic sludge, and then a cement-based solidification agent and an elution inhibitor made by chelate bonding an iron salt with a protein hydrolysate are added to perform solidification. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a soil-and-sand substitute material that can be used in place of a natural soil-and-sand material mainly composed of inorganic sludge.

Inorganic sludge generated by excavation and drilling at civil engineering sites is rarely reusable as banking, etc., and has been landfilled in a managed final disposal site mainly by drying and dehydrating in the sun. However, the management-type final disposal site is in a situation where the remaining capacity has become tight in recent years. On the other hand, materials such as gravel and soil used as civil engineering materials have been collected by excavating mountains and seas, but in recent years it has become difficult to collect them from the viewpoint of protecting the natural environment.
Therefore, recycling of inorganic sludge has been studied, and some technologies that have been developed are presented. The technology disclosed in Patent Document 1 is a stable and homogeneous material that can be dehydrated, granulated and solidified in a short time from a large amount of sludge discharged from the excavation method for civil engineering and difficult to reuse. The purpose is to provide a sludge recycling method and its recycling equipment that regenerates as a performance resource, using sludge dehydrated and reduced in water content as a raw material, using a solidifying agent as an additive, When stirring and kneading at high speed with a mixing blade, sludge particles and residual water are further separated by centrifugal force, and a large number of fine particles of sludge are combined with a solidifying agent to increase the particle size and granulate and solidify.
In addition, the technology disclosed in Patent Document 2 is a method in which inorganic sludge generated in civil engineering construction is subjected to intermediate treatment such as sun drying and dehydration, and then cement, fine aggregate, coarse aggregate, water and after-stirring type in a concrete plant. It is poured into a frame and crushed with a crusher after curing, to obtain recycled crushed stone.
However, the conventional technology is in a situation where the recycling as a soil and sand substitute material is weaker than natural materials and the cost of production is high, so that the recycling is hardly realized. In addition, these techniques have not been adapted to elution of harmful substances by rainwater after use.

The technique disclosed in Patent Document 3 recognizes the problem of preventing elution of harmful substances, and provides a technique for changing a substance contained in an object to be processed from an easy elution state to a difficult elution state. According to the present invention, a weathered product of a descending volcanic eruption containing allophane is mixed with an object to be treated containing a substance that is easily eluted in water, and the substance that easily dissolves in water and the descending volcanic eruption in the mixture It forms a difficult-to-elute chemical complex by binding to the weathered product. However, the element concentrations shown are only for boron, fluorine, arsenic, and selenium, and the elution prevention effect for heavy metals, which is the initial purpose, cannot be confirmed. Also, considering that allophane is mainly responsible for the elution prevention effect, how much it is contained in pumice and the like will vary depending on the collected pumice, and those skilled in the art will understand this specification. It cannot be said that disclosure has been made to the extent that it can be easily implemented.
Japanese Patent Laid-Open No. 9-294998 “Sludge Recycling Method and Recycling Apparatus” Published on November 18, 1997 JP 2000-33399 A "Recycling of construction sludge" Published February 2, 2000 JP 2006-263509 A “Method for Immobilizing Substances Easily Eluted in Water, and Materials Obtained thereby” Published on Oct. 5, 2006

  The problem of the present invention is that the strength as a soil-and-sand substitute is comparable to that of natural materials, and the manufacturing cost is commensurate with the profit, and the inorganic sludge in which the elution of toxic substances such as heavy metals is prevented. The purpose is to provide a method for producing a soil and sand substitute material as a main raw material.

The method for producing a soil-and-sand substitute material using the inorganic sludge of the present invention as a main raw material is: among recycled sludge of sandy molten slag, concrete glass, glass, earthenware, and silty coal ash, gypsum After mixing at least one auxiliary agent with inorganic sludge, a cement-based solidifying agent and a protein hydrolyzate were added with an elution inhibitor obtained by chelating iron salt to solidify the mixture.
Moreover, in the manufacturing method of the earth-and-sand substitute material which uses this inorganic sludge as a main raw material, when the inorganic sludge contained the water | moisture content, it was made to use as a dewatering cake.
In addition, in the method for producing a soil and sand substitute material using inorganic sludge as a main raw material, as a method for forming the earth and sand substitute material to a desired particle size, a method of using a granulator when solidifying and a method of solidifying A method of forming a large lump and then forming it into a desired particle size using a crusher is presented.

The manufacturing method of the earth and sand substitute material using the inorganic sludge of the present invention as the main raw material is based on the conventional management type by manufacturing the earth and sand substitute material using the inorganic sludge as the main raw material and using industrial waste as an auxiliary material. Inorganic sludge and industrial waste that have been landfilled at stable final disposal sites can be recycled as environmentally safe materials, contributing to the extension of life of managed and stable final disposal sites. can do.
Since the method for producing a soil-and-sand substitute material using the inorganic sludge of the present invention as the main raw material uses a protein hydrolyzate chelated with an iron salt as an elution inhibitor, the inorganic sludge is used as the main raw material. Even if an auxiliary material using industrial waste is used, harmful substances such as heavy metals contained therein can be effectively prevented from leaching, and an environmentally safe and high-quality soil substitute material can be produced. That is, it can greatly contribute to the protection of the natural environment.

Hereinafter, the present invention will be described based on the embodiment shown in the accompanying drawings. FIG. 1 is a schematic explanatory diagram illustrating the steps of a method for producing a soil and sand substitute material using inorganic sludge as a main raw material according to the first formability of the present invention. Inorganic sludge A, the main raw material, is generated when construction sludge discharged by shield excavators or boring machines, dredged sludge discharged when dredging rivers and ponds, and when crushed stones are washed in quarries. Crushed stone sludge containing soil. The auxiliary material B is sandy molten slag, concrete glass, glass, recycled resources obtained by crushing earthenware, silty coal ash, gypsum, etc., and at least one of these is mixed with inorganic sludge A. Solidify. In the solidification, the auxiliary material B serves as a core, and the earth and sand substitute material E is formed, so that a high-quality earth and sand substitute material that increases its strength and is not inferior to a natural material can be manufactured. In particular, as the auxiliary material B added to the inorganic sludge A, it was confirmed that when a mixture of molten slag and coal ash with substantially equal weight was used, a soil and sand substitute material having high mechanical strength was generated.
As the solidifying material C used in the present invention, a cement-based solidifying material or an inorganic solidifying material such as quicklime or slaked lime is used. Anti-elution agent D is a chemical that is used for the purpose of satisfying the standard of “Environmental Standards Concerning Soil Contamination” when cement-based solidifying material is used as solidifying material C, and suppresses elution of heavy metals and the like. This is for producing earth and sand substitute material E that is safe for the environment. It is an extremely important technical matter to determine what kind of anti-elution agent is used to effectively prevent the elution of harmful substances. In the present invention, the elution inhibitor D obtained by chelating a protein salt with an iron salt is used.

A first embodiment of the present invention will be described with reference to FIG. At least one of the inorganic sludge A and the auxiliary material B as described above is put into a granulating apparatus 2 having a function of crushing, mixing, kneading, and granulating, and after crushing and mixing, The solidifying material C is added to the granulating apparatus 2 in an amount of 4 to 18% of the total weight, followed by mixing, kneading and granulating steps to granulate and solidify. At this time, the auxiliary material B serves as a core and increases the strength of the earth and sand substitute material E. At this time, when a harmful substance is detected in the inspection from the inorganic sludge A and the auxiliary material B to be used, the dissolution inhibitor D is put into the granulator 2 during the kneading process. In the present invention, elution of heavy metals and the like can be effectively suppressed by using the above-described protein hydrolyzate obtained by chelating an iron salt to the dissolution inhibitor D, which is environmentally safe and of high quality. The earth and sand substitute material E can be manufactured. Further, in the embodiment shown in FIG. 1, depending on the case, at least one of the inorganic sludge A and the auxiliary material B may be put into the granulator 2 almost simultaneously with pulverization / mixing / kneading. -Granulation and solidification may be performed through a granulation process.
The manufacturing method of the earth-and-sand substitute material which uses the inorganic sludge as a main raw material by the 2nd form of implementation of this invention is a case where the inorganic sludge A containing a lot of water | moisture contents is used. In that case, as shown by the broken line in FIG. 1, the inorganic sludge A is not directly fed into the granulator 2, but the dehydrated cake that has been dehydrated by being fed into the dehydrator 1 is put into the granulator 2. To step on. Since other steps and operations are the same as those described in the above-described embodiment, a duplicate description is omitted.

FIG. 2: is schematic explanatory drawing which shows the process of the manufacturing method of the earth-and-sand substitute material which uses the inorganic sludge as a main raw material by 3rd Embodiment of this invention. In addition, the same code | symbol is attached | subjected to the material which has the same function as what was demonstrated in previous embodiment, and the overlapping description is abbreviate | omitted. At least one of the inorganic sludge A and auxiliary material B, which has been put forward, is put into a mixing / kneading machine 3 having a function of crushing / mixing / kneading and pulverized / mixed. Is added to the mixing / kneading machine 3 in an amount of 4 to 18%, and the mixing / kneading step is performed. This is poured into a suitable container and solidified in the form of a lump. After solidifying, the solidified material is crushed by using the crusher 4 to obtain particles of an appropriate size, and the earth and sand substitute material E is produced. At this time, when a harmful substance is detected in the inspection from the inorganic sludge A and the auxiliary material B to be used, the dissolution inhibitor D is introduced into the mixing / kneading machine 3 during the kneading process. Also in this embodiment, the elution inhibitor D obtained by chelating an iron salt to a protein hydrolyzate is used as in the previous example. Thus, elution of heavy metals and the like can be effectively suppressed, and the environment-safe and high-quality earth and sand substitute material E can be produced as in the previous example. Also, in the embodiment shown in FIG. 2, depending on the case, at least one of the inorganic sludge A and the auxiliary material B is almost simultaneously added to the mixing / kneading machine 3 for crushing / mixing. -The kneading and granulating steps may be followed by granulation and solidification.
The manufacturing method of the earth and sand substitute material which uses the inorganic sludge as a main raw material by the 4th form of implementation of this invention is a case where the inorganic sludge A containing a lot of water | moisture contents is used. In that case, as shown by the broken line in FIG. 2, the inorganic sludge A is not directly fed into the mixing / kneading machine 3, but the dehydrated cake that has been put into the dehydrating apparatus 1 and dehydrated is fed into the mixing / kneading machine 3. Take steps to do.

FIG. 3: is schematic explanatory drawing which shows the process of the manufacturing method of the earth-and-sand substitute material which uses the inorganic sludge by the 5th Embodiment of this invention as a main raw material. In addition, the same code | symbol is attached | subjected to the material, apparatus, and apparatus which have the function similar to what was demonstrated in embodiment mentioned above, and the overlapping description is abbreviate | omitted. At least one kind of the inorganic sludge A and auxiliary material B, which has been put forward, is put into the mixing / kneading machine 3 and pulverized / mixed, and then the solidified material C is mixed / kneaded in an amount of 4-18% of the total weight. The machine 3 is charged and the mixing and kneading steps are performed. Then, it sends to the granulator 2 and is made to granulate and solidify, and the earth-and-sand substitute material E is manufactured. Also in this embodiment, the elution inhibitor D obtained by chelating an iron salt to a protein hydrolyzate is used as in the previous example. Thus, elution of heavy metals and the like can be effectively suppressed, and the environment-safe and high-quality earth and sand substitute material E can be produced as in the previous example.
In the embodiment shown in FIG. 3, after at least one kind of inorganic sludge A and auxiliary material B and solidifying material C are introduced into the mixing / kneading machine 3 almost simultaneously, and the steps of crushing / mixing / kneading are performed. Alternatively, the soil and sand substitute material E may be produced by sending it to the granulating device 2 and granulating and solidifying, and if necessary, the elution preventing material D may be added to the mixing and kneading machine 3 in the kneading process to remove heavy metals, etc. Sediment substitute material E is produced while suppressing elution.
The method for producing a soil-and-sand substitute material using inorganic sludge as a main raw material according to the sixth embodiment of the present invention is a case where inorganic sludge A containing a large amount of water is used. In that case, as shown by the broken line in FIG. 3, the inorganic sludge A is not directly fed into the mixing / kneading machine 3, but the dehydrated cake that has been put into the dehydrating apparatus 1 and dehydrated is fed into the mixing / kneading machine 3. Take steps to do.

この原料を図１に示す実施形態１によって造粒固化して土砂代替材を製造したものを試料として県の認定試験機関（株式会社南西環境研究所）に依頼して溶出試験を行った。その際の結果を表２に示す。

検査方法は最右欄に示される方法によってなされ、１リットル当たりの含有量に換算して環境基準値と比較させて本実施例の結果を示している。なお、この基準値＊１は平成３年８月環境庁告示第４６号（最終改正：平成１３年３月環境省告示第１６号）によるもの、計量方法における環告第６４号＊２は環境大臣が定める排水基準に係る検査方法であって、昭和４９年９月環境庁告示第６４号（最終改正：平成１３年６月環境省告示第３７号）、環告第５９号＊３は環境大臣が定める水質汚濁に係る環境基準の検査方法であって、昭和４６年１２月環境庁告示第５９号（最終改正：平成１５年１１月環境省告示第１２３号）、総理府令第６６号＊４は農用地土壌汚染対策地域の指定要件に係る銅の量の検定の方法を定める省令であって、昭和４７年１０月総理府令第６６号（最終改正：平成１２年８月総理府令第９４号）によるものである。この溶出試験結果の中で、コンクリート系物質から溶出されやすい有害物質として六価クロムは基準値0.05以下の0.04，セレンは基準値0.01以下の0.004，そしてホウ素は基準値１以下の0.01であった。その他の重金属などいずれの着目物質についても環境基準をクリアーしていることが確認できた。 An example of a soil and sand substitute material using inorganic sludge produced by the present invention as a main raw material will be reported. Crushed stone sludge, desulfurized gypsum and ordinary portrant cement are put into a granulator, crushed and mixed, and then an elution inhibitor made by chelating iron salt with the protein hydrolyzate according to the present invention is put into the granulator. Then, by carrying out a kneading and granulating process, the granulated solidified material was produced. The blending ratio of raw materials and the like in this example is as shown in Table 1.

The raw material was granulated and solidified according to Embodiment 1 shown in FIG. 1 to produce a soil and sand substitute material, and a dissolution test was conducted by requesting a prefectural authorized testing organization (Nanbu Environmental Research Institute Co., Ltd.). The results are shown in Table 2.

The inspection method is performed by the method shown in the rightmost column, and the result of this example is shown by converting the content per liter and comparing it with the environmental standard value. This standard value * 1 is based on the Environment Agency Notification No. 46 (final revision: Ministry of the Environment Notification No. 16 March 2001), and the Notification Method No. 64 * 2 in the measurement method is the environment. This is an inspection method according to the wastewater standards set by the Minister, and the Environment Agency Notification No. 64 (Final Revision: Ministry of the Environment Notification No. 37 in June 2001) and Notification No. 59 * 3 This is an inspection method for environmental standards related to water pollution established by the Minister. Environment Agency Notification No. 59 in December 1971 (final revision: Ministry of the Environment Notification No. 123 in November 2003), Prime Minister's Ordinance No. 66 * 4 is a ministerial ordinance that establishes the method of testing the amount of copper pertaining to the designated requirements for agricultural land and soil pollution control areas. In October 1972, Prime Minister's Ordinance No. 66 (final revision: Prime Minister's Ordinance No. 94 in August 2000) ). Among the leaching test results, hexavalent chromium as a harmful substance that is likely to be eluted from concrete materials was 0.04 with a reference value of 0.05 or less, selenium was 0.004 with a reference value of 0.01 or less, and boron was 0.01 with a reference value of 1 or less. . It was confirmed that the environmental standards were cleared for all the substances of interest such as other heavy metals.

Moreover, the cone index test about the earth-and-sand substitute material produced | generated by this Example was requested from the authorized test organization (Civil Engineering Co., Ltd.) of the prefecture. The cone index is a value obtained by dividing the force required for penetrating the cone-venometer to a certain depth in the soil by the bottom area of the cone. In a cone index test conducted in accordance with JIS A 1228, a result of 1,939 KN / m ³ was obtained. The soil classification criteria stipulated by the Ministry of Construction Ordinance are as shown in Table 3, and this value is the standard value for Type 2 construction generated soil (sandy soil, gravelly soil and similar materials), 800 KN / m It was a big clear of ³ or more.

この原料を図１に示す実施形態２によって造粒固化して土砂代替材を製造したものを試料として県の認定試験機関（株式会社南西環境研究所）に依頼して溶出試験を行った。その際の結果を表５に示す。

この溶出試験結果の中で、コンクリート系物質から溶出されやすい有害物質として六価クロムは基準値0.05以下の0.01，セレンは基準値0.01以下の0.001，そしてホウ素は基準値１以下の0.01であった。その他の重金属などいずれの着目物質についても環境基準をクリアーしていることが確認できた。 Another embodiment of a soil and sand substitute material using inorganic sludge produced by the present invention as a main raw material will be reported. The sludge discharged from the construction site (water content ratio 400%) is treated in the second embodiment of the present invention shown in FIG. Since it cannot be used as it is because of its high water content like muddy water, it is first dehydrated with the dehydrator 1 and dehydrated cake (moisture content 67%), molten slag and blast furnace cement B type are put into the granulator 2. After pulverizing and mixing, an antielution agent obtained by chelating iron salt to the protein hydrolyzate according to the present invention is added to the granulating device 2 and the kneading and granulating process is mixed and granulated and solidified to replace soil The material was manufactured. In addition, the blending ratios of the raw materials and the like in this example are as shown in Table 4.

The raw material was granulated and solidified according to Embodiment 2 shown in FIG. 1 to produce a soil and sand substitute material, and a dissolution test was conducted by requesting a prefectural authorized test organization (Southwest Environmental Research Institute Co., Ltd.). The results are shown in Table 5.

Among the leaching test results, hexavalent chromium as a hazardous substance that is likely to be eluted from concrete-based materials was 0.01 with a reference value of 0.05 or less, selenium was 0.001 with a reference value of 0.01 or less, and boron was 0.01 with a reference value of 1 or less. . It was confirmed that the environmental standards were cleared for all the substances of interest such as other heavy metals.

Moreover, the corn index test about the earth-and-sand substitute material produced | generated by this Example was conducted by requesting the accredited test organization (Okinawa Prefecture Construction Technology Center). A cone index test of compacted soil conducted in accordance with JIS A 1228 yielded a result of 1,657 KN / m ³ . This value was obtained by increased cleared 800 kN / m ³ or more is a reference value of the second type of construction waste soil (sandy soil, gravelly soil and equivalent thereto).

  According to the test results of the above examples, according to the method for producing a soil and sand substitute material using the inorganic sludge of the present invention as a main raw material, the strength as a soil and sand substitute material is comparable to that of a natural material, and the production cost is also low. In addition to being profitable, it was confirmed that a method for producing a soil and sand substitute material using inorganic sludge in which elution of toxic substances such as heavy metals was prevented as a main raw material could be provided. In particular, it is significant that we have confirmed the safety of hexavalent chromium as a harmful substance that is easily eluted from concrete materials.

It is a block diagram explaining 1st Embodiment and 2nd Embodiment of this invention. It is a block diagram explaining 3rd Embodiment and 4th Embodiment of this invention. It is a block diagram explaining 5th Embodiment and 6th Embodiment of this invention.

Explanation of symbols

A Inorganic sludge B Auxiliary material C Solidified material D Elution inhibitor E Sediment substitute 1 Dehydrator 2 Granulator 3 Mixing / kneading machine 4 Crusher

Claims (4)

  After mixing the sludge with sandy molten slag, concrete glass, glass, recycled resources obtained by crushing pottery, silt coal ash, and at least one auxiliary agent of gypsum into the inorganic sludge, cement type A method for producing a soil-and-sand substitute material comprising, as a main raw material, inorganic sludge obtained by solidifying a solidifying agent and a protein hydrolyzate by adding an elution inhibitor obtained by chelating iron salt.   When the inorganic sludge contains moisture, it is used as a dehydrated cake. The method for producing a soil and sand substitute material using inorganic sludge as a main material according to claim 1.   The method for producing a soil-and-sand substitute material using inorganic sludge as a main raw material according to claim 1 or 2, wherein the solidified material is formed into a desired particle size using a granulator.   3. The method for producing a soil-and-sand substitute material using inorganic sludge as a main material according to claim 1 or 2, which is formed into a large lump when solidified and then formed into a desired particle size using a crusher.

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